About the event arrivals search

Use this page to search for arrivals/phase data within the ISC bulletin. Data can be returned both for specific stations and for specific events. Returned data for individual arrivals at each station includes arrival times, travel-time residuals, a flag for time-defining phases, amplitudes, and the prime hypocentre for each event.

Database

Reviewed ISC Bulletin:

A subset of the ISC Bulletin that has been manually reviewed by ISC analysts. This includes all events that have been relocated by the ISC. For more information on the Reviewed ISC Bulletin, see here.

ISC Bulletin:

The entire ISC Bulletin from both reviewed and unreviewed events. This includes the most recent events, which have yet to be reviewed.

Output format

CSV formatted arrivals:

A fixed format, comma separated output, with one line per arrival. For a full explanation of each field, see the csv arrivals output page .

IMS1.0 associated arrivals:

The International Monitoring System 1.0 (IMS1.0) is a fixed format output for exchanging data, developed for use in monitoring the Comprehensive Test Ban Treaty. The 'associated arrivals' is a subtype within this format that lists arrivals associated to an event. For a full explanation of the format, please view the IMS1.0 documentation available here.

QuakeML:

QuakeML is an XML representation of seismological data. Data are output as an XML stream using the QuakeML XML Schema, version 1.2. Similar to the CSV output, only the prime origin are output for each event. This output is not designed for use in a browser and will cause browsers to crash for large queries. For a complete explanation of the schema, please view the documentation on the QuakeML site.

Search arrivals

Arrival-time data:

If ticked, only arrivals with arrival-time data will be returned (some amplitudes do not have an arrival-time).

Travel-time residuals:

If ticked, only arrivals with ISC determined travel-time residuals will be returned. Travel-time residuals are only computed for events within the Reviewed ISC Bulletin. Before 1st January 2006, travel-time residuals were computed with from the JB Earth model. Since 1st January 2006, travel-time residuals are computed from the ak135 Earth model.

Time-defining phases:

If ticked, only arrivals which are time-defining will be returned. Time-defining phases are those phases which are used in the computation of the prime hypocentre. Defining phases only exist for events with an ISC authored hypocentre.

Amplitude data:

If ticked, only arrivals with amplitudes will be returned.

Phase name:

By specifying a specific phase name (or list of phases), only arrivals from those phases will be returned (E.g. P, Pg, PKPdf, S, etc. ). The standard nomenclature for seismic phases approved by IASPEI is detailed in Storchak et al. (2003) and are listed here.

To specify stations to search for arrivals, you may either provide a station code (or a list of station codes in a comma separated list), or you may define a search region (rectangular, circular, global, Flinn-Engdahl region), which will search stations from the International Registry of Seismograph stations.

Search region for EVENTS

There are four possible methods for defining a search region (rectangular, circular, global, Flinn-Engdahl region). Leaving fields blank, will automatically default to a global search. To interactively define a search region, using customised shapes, please use the interactive search page. The defined region is used to check only the prime hypocentre.

Time period

This is the start and end date to search for events. Only the prime hypocentre will be searched to match events - i.e. origin times for secondary hypocentres will not influence the results.

Unknown depths

As some events have no determined depth, you may optionally choose to include events with unknown depths in the search. This will return events which match any selected depth constraint you enter as well as events with no depth.

Unknown magnitudes

As some events have no determined magnitude, you may optionally choose to include events with unknown magnitude values in the search. This will return events which match any selected magnitude constraint you enter as well as events with no magnitude value.

Magnitude type

Limit events by magnitude for specific magnitude types. Due to the large number of magnitude types and the various notation used, the selected type will search all magnitudes of that type. E.g. MB will match all body-wave magnitudes: mb, mB, MB, mb1mx, etc.

Magnitude author

Limit events by magnitude values determined by a specific author. ISC, NEIC, GCMT/HRVD and JMA amongst others are considered reliable magnitude authors. The default uses 'Any', which will match any author that has a magnitude for both prime and secondary hypocentres included in an event. Selecting 'prime author' will limit the search to magnitudes directly associated with the prime hypocentre (usually the same author as the prime hypocentre) - i.e. for events with an ISC authored prime hypocentre, selecting 'Prime author', will limit events to those with ISC determined magnitudes (and any min/max value specified). For more information on any of these agencies, please visit the contributing agencies page.

E.g. To search for events with MW >= 6, you may want to specify the magnitude author to be GCMT as there may be few events where the 'prime author' has computed a moment magnitude.

Please note: selecting either GCMT or HRVD, will return results from both agencies, as GCMT is a continuation of HRVD.

Output links

This provides links for each event to the full Bulletin listing. There are also links for each author to provide the full agency details.